Subject: Re: [vserver] Sponsoring VServer getting up to date with mainline
From: "Daniel Hokka Zakrisson" <daniel@hozac.com>
Date: Fri, 22 Aug 2008 21:30:17 +0200 (CEST)

Herbert Poetzl wrote:
> On Fri, Aug 22, 2008 at 06:57:55PM +0100, Ed W wrote:
>> Herbert Poetzl wrote:
>> >situation: one of my raid controllers suddenly failed
>> >and I need to replace it with a new one (currently
>> >the raid is offline, and I don't have access to the
>> >data). as I was not very happy with the controller
>> >(an Intel/LSI one, which only caused issues from the
>> >beginning), I want to replace it with a different
>> >model from Adaptec (specifically the RAID 31605),
>> >which seems to have good support and all the features
>> >I am looking for.
>>
>> Just an aside, but can I ask why a fancy raid controller?
>
> that's simple, with 12+ disks you have almost no
> chance to attach them to _any_ motherboard ...
>
> besides that, normal SATA controllers do not have
> the bandwith to get performant I/O over e.g.
> port multipliers, so the only choice is a big
> throughput raid controller ... note that I could
> live without the fancy hardware raid features,
> but you really don't get any 8-16 port SATA
> controller without hardware raid ...

For this, I use Supermicro's AOC-SAT2-MV8. It's an 8-port card that costs less than
100
USD, though it does require a PCI-X slot. Granted it's got a Marvell chipset, but I
haven't had any problems with it.

> note that disk I/O is the main bottleneck of
> todays servers/machines, and compiling kernels
> means moving a lot of data from/to disk
>
>> I personally LOVE the top end stuff, for example have some very good
>> experiences with Compaq battery backed scsi controllers. But I have
>> had nothing but disappointment with even decent 3Ware controllers
>> and I notice no difference at all over builtin SATA controllers,
>> which coupled with a nice motherboard often mean you can have 8-10
>> controllers right on the bridge and hence high speed access
>>
>> Battery backup is missing off the onboard controllers though and if
>> you have a DB application (probably not if you are getting 1.5GB
>> disks) then this is a big deal, but otherwise it's not likely to make
>> much difference (hey not teaching you to suck eggs - I'm sure you
>> already know if it will help your workload!)
>
> yes, as mentioned, it definitely helps my specific
> workload to maximize disk I/O and minimize latency
>
>> In summary though unless you need the battery backup I would recommend
>> a new motherboard with enough onboard ports to meet your needs -
>> forget what I have but I bought some bits of the office machine and it
>> supports my quad intel thing with I think 8+ sata ports?
>
>> > and I could
>> >also make good use of three or four of those new
>> >1.5TB SATA disks from Seagate (ST31500341AS) or the
>> >1TB models (ST31000340AS) to retire one of my older
>> >disk arrays (150-200 USD/ 120-150 EUR each)
>>
>> The 1.5TB have quite a price hike, even the 1TB are I think slightly
>> above the sweet spot still? I just bought 5x 1TB drives and the
>> Samsung spinpoints were the best value - not had any problems with
>> them so far, but don't load them much either.
>
> the 1TB disks specified above have 32MB cache, 5 years
> of manufacturer warranty, they don't suck power, and
> most important, this series has been working for me
> for some time now (the price is roughly 0.12 EUR/GB,
> where e.g. a U320 SCSI disk ranges at 1.2 EUR/GB :)
>
> note that the Samsung F1 Raid costs more than the
> Seagate model, and I'm not convinced about the SpinPoint
> series, as they had bad publicity (overheating and such)

Here, the Samsung drives are cheaper. As for the risk of overheating, my Seagate drives
are warmer than my Samsung drives, even though the Samsung disks are under "heavier"
load. But whatever you're the most comfortable with is best... after all, it is your
data :-)

-- 
Daniel Hokka Zakrisson